1. Field of the Invention
The instant invention generally relates to a wind power generator and is more particularly concerned with a vertical axis wind turbine with a rotor assembly and rotatable housing.
2. Description of Related Art
In relation to prior art, currently existing devices that are used to recover wind power and transform it into mechanical or electrical energy can be classified, according to its axis position, as horizontal axis or vertical axis, suffering both types from several disadvantages, sufficiently overcame by the improvements of the present invention.
As is known, today's horizontal axis devices stand in general at a considerable height and are located in very high areas and almost always in the very parting planes of mountain slopes, mountain ranges or massifs, with the consequent undesired visual impact. They can also cause severe damage to wildlife, especially to flying species, due to their large blades. These negative factors are determinant for the installation of wind power plants nowadays, versus ecologist requirements. Improvements in the present invention enable a person skilled in the art to build devices with high wind power recovery, low height and not harmful to flying species.
Today's horizontal and vertical axis devices also produce a characteristic noise when the assembly blades are turning, which can become serious when considering the installation of a wind power plant with a large number of power devices. The mentioned improvements achieve a less noisy device, and therefore no noise pollution of the environment is produced when several of these devices are installed in a specific area.
The fact that periodic wind regimes differ according to place, time of day, seasons, meteorology at a given moment and topography of the site must be taken into account when deciding the location of today's wind power recovery devices. However, the features of the device to which the improvements of the present invention apply enable to place it, without any difficulty or performance reduction, in areas with high or low wind speed, and regardless of the wind direction.
The improvements of the present invention enable to reduce the main drawbacks of vertical axis wind turbines, such as mechanical fatigue and the presence of natural resonance frequencies, as well as the fact that rotation coupling presents variations in every cycle. Another additional problem of vertical axis devices, and also reduced with the incorporation of the present improvements, is that they require motorization in order to overcome the high breakaway torque.
Patent No. P 9300316 “Wind Turbo Generator” presents a large hopper applied to a horizontal axis wind turbine so that it is also used with low speed winds, but due to such large hopper produces a significant visual and sound impact.
Patent No. P 055984 “System to enhance the performance of a vertical axis aerogenerator” produces also an important visual impact due to the fact that it stands taller than the devices of the mentioned improvements, and has a lower performance.